Throatless power rotary shears

ABSTRACT

An easy to use power rotary shear is disclosed to facilitate cutting rigid and semi-rigid sheeted materials, such as rigid sheeted materials including the likes of metal roofing, or other rolled or formed sheet metal, sheeted semi-rigid plastics, fiberglass, and the like, as well as a method of making same, and a method of using it. This includes utilizing a portable single handed, weight balanced, smooth cutting power rotary shear. One specific preferred aspect has certain features including a v-shaped relief behind the rotary cutting blades that automatically separates the pieces generated by the cutting operation. Cutting rigid sheeted materials, especially large pieces, is made almost effortless with the inclusion of this motorized power rotary shear that can be operated with one hand, while holding the workpiece with the other hand.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C. 119(e) of U.S. Provisional Application Ser. No. 63/052,241, filed on Jul. 15, 2020.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT

Not Applicable

INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC OR AS A TEXT FILE VIA THE OFFICE ELECTRONIC FILING SYSTEM (EFS WEB)

Not Applicable

STATEMENT REGARDING PRIOR DISCLOSURES BY THE INVENTOR OR A JOINT INVENTOR

Not Applicable

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a throatless power rotary shear, methods of manufacturing same, and methods of using same. More particularly, the invention relates to a motorized power rotary shear useful for cutting sheet metal and other sheeted materials.

2. Description of the Prior Art

Conventional metal shears are well known in the art, including one of the most common types of hand operated shear. Use of such a shear poses problems for operators because sharp edges can cut their hand, and getting a smooth cut is truly problematic.

However, practitioners of those inventions have become aware of certain problems which are presented by those prior art inventions. One particular problem that has plagued users has been that it is difficult to separate the pieces generated by the shears once the cut has been made. Further, it has been very difficult to back the blade out of the cut, and it has been very difficult to make accurate angled cuts. There are complexities which give rise to injuries and physical disabilities.

It would be of a great advantage to the construction industry if there was provided an easy to use power rotary shear mechanism, and method of making it, as well as a method of using it.

SUMMARY OF THE INVENTION

In accordance with the above-noted advantages and desires of the industry, the present invention provides an easy to use power rotary shear to facilitate cutting rigid and semi-rigid sheeted materials, such as rigid sheeted material including the likes of metal roofing, or other rolled or formed sheet metal, sheeted rigid plastics, fiberglass, and the like, as well as a method of making same, and a method of using it. This includes utilizing a portable single handed, weight balanced, smooth cutting power rotary shear. This overcomes many of the aforementioned problems with the prior art because cutting rigid sheeted materials is no longer a dangerous activity.

One specific preferred aspect has certain features including a v-shaped relief behind the rotary cutting blades that automatically separates the pieces generated by the cutting operation. Cutting rigid sheeted materials, especially large pieces, is made almost effortless with the inclusion of my motorized power rotary shear that can be operated with one hand, while holding the workpiece with the other hand. By including a reversible motor, backing out after making a cut that does not need to cut all the way to the full length of the sheeted material is much easier.

The invention is particularly useful for applications in the contractor and construction industries that require the cutting and fitting of large pieces of metal roof, plastic sheeting for shower stalls, as well as any other large piece of rigid sheeted long construction material. The applications are too numerous to mention here.

Although the invention will be described by way of examples hereinbelow for specific aspects having certain features, it must also be realized that minor modifications that do not require undo experimentation on the part of the practitioner are covered within the scope and breadth of this invention. Additional advantages and other novel features of the present invention will be set forth in the description that follows and in particular will be apparent to those skilled in the art upon examination or which may be learned within the practice of the invention. Therefore, the invention is capable of many other different aspects and its details are capable of modifications of various aspects which will be obvious to those of ordinary skill in the art all without departing from the spirit of the present invention. Accordingly, the rest of the description will be regarded as illustrative rather than restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

For a further understanding of the nature and advantages of the expected scope and various aspects of the present invention, reference shall be made to the following detailed description, and when taken in conjunction with the accompanying drawings, in which like parts are given the same reference numerals, and wherein:

FIG. 1 is a side perspective view of a throatless power rotary shear, in use, cutting a sheeted material, the throatless power rotary shear being made in accordance with the present invention;

FIG. 2 illustrates a side elevational view of the throatless power rotary shear with details of the V-shaped relief behind the wheels;

FIG. 3 is a side elevational view of the throatless power rotary shear being used to cut a piece of corrugated metal roofing panel;

FIG. 4 is a rear perspective view of the throatless power rotary shear, in use, cutting a sheeted material in front of a corrugated portion;

FIG. 5 is a close-up view of the meshing of the rotary cutting blades;

FIG. 6 shows an aspect of the beveled gear motor mechanism to create rotary action;

FIG. 7A is a close-up view of the relative placement of the rotary blades;

FIG. 7B is a close-up view of the relative placement of the v-shaped relief behind the rotary blades;

FIG. 8 is a rear elevational view of the relative placement of all components;

FIG. 9 shows another aspect of the present invention suitable for mounting, shown here as mounted on a sawhorse.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings in detail, FIG. 1 is a side perspective view of a throatless power rotary shear used for cutting a sheeted material, the throatless power rotary shear being made in accordance with the present invention. FIG. 1 shows the throatless power rotary shear generally indicated by the numeral 10, which includes a motor 12, a handle 14 and a trigger 16 in a position that enables the throatless power rotary shear to be operated in a one-handed fashion. The throatless power rotary shear includes an s-shaped frame 18 that accommodates feed wheel 20 and cut wheel 22. Cut wheel shaft 24 secures cut wheel 22 during operation, while feed wheel transmission shaft 28 secures feed wheel 20 during operation. Feed wheel guard 26 helps to prevent dangerous splintering of materials, in order to protect the operator. Sheeted rigid material 30 is easily cut by throatless power rotary shear 10, and will be described more fully herein below.

Looking next to FIG. 2 , a side elevational view of the throatless power rotary shear illustrates how sheeted corrugated rigid material 30 is fed between cutting wheel 22 and feed wheel 20. As before, handle 14 is mounted onto or near motor 12 with trigger 16. The motor may be activated in a cordless fashion, or a traditional electric cord connection. Feed wheel 20 is driven in a rotary fashion by feed wheel transmission shaft 28, while feed wheel 22 is driven by cut wheel shaft 24. Housing 26 and lower portion of the s-shaped frame 18 help to prevent injuries from flying bits during the cutting operation. Distance A-A exists between the end of the contact point between the feed wheel 20 and cutting wheel 22 and the s-shaped frame. The gap defined by distance A-A may range from ⅛ inch to 1 inch, and is preferably about three quarters of an inch for corrugated metal roofing materials. This gap helps to separate the material after it has been cut. For some materials, the gap A-A would need to be relatively small, where for other materials, gap A-A needs to be larger in order to provide smooth flow of cut material. Regarding the overlap of feed wheel 20 and cut wheel 22, less overlap means that one can cut through bent materials much more easily. Although the overlap can be as little as 1.0 mm, it can be as much as one inch (1″), and may preferably be “0.032” for certain applications. When cutting corrugated materials, the throatless power rotary shear preferably would have a lesser overlap of the wheels in order to accommodate the corrugated incline part 34 of the rigid sheeted material 30 more easily. A v-shaped relief behind the wheels will provide a better direct flow of cut material, resulting in a smoother cut. The v-shaped relief is defined by gap A-A as shown in FIG. 2 , and is essentially adjacent to the cutting wheels.

FIG. 3 is described with like element numbers to those described in FIG. 2 above, although FIG. 3 illustrates cutting the corrugated incline part 34 of sheet metal 30 between the feed wheel 20 and cut wheel 22. As can be seen in this figure, and due to a minimum overlap between cut wheel 22 and feed wheel 20, corrugated incline part 34, as it is urged between the two wheels, can follow the shape of the corrugated incline part 34, while gap A-A is defined by the v-shaped relief behind the wheels (not shown in this figure). The v-shaped relief will be described more fully hereinbelow in FIG. 7A and FIG. 7B. Again as before with reference to FIG. 2 above, handle 14 is mounted onto or near motor 12 with trigger 16. The motor may be activated in a cordless fashion, or a traditional electric cord connection. Feed wheel 20 is driven in a rotary fashion by feed wheel transmission shaft 28, while feed wheel 22 is driven by cut wheel shaft 24. Housing 26 and lower portion of the s-shaped frame 18 help to prevent injuries from flying bits during the cutting operation.

Looking next to FIG. 4 , another view of the throatless power rotary shear of the present invention is once again shown cutting corrugated sheeted roofing material 54. The throatless power rotary shear is generally denoted by numeral 40 which includes motor 42 connected to handle 44 and trigger 46. Transmission cover 48 is secured by transmission cover housing 50 in direct contact with feed wheel guard 52. Sheeted workpiece panel 54 is being fed between cut wheel 58 and the feed wheel which is not shown in this picture. Cut wheel shaft 56 rotates cut wheel 58. Cut wheel guard 60 prevents dangerous flying pieces in order to protect the operator. When trigger 46 is activated, power is delivered by electric cord 62 and the cutting operation begins. Cut material from the sheeted workpiece panel 54 will be guided to separate the cut pieces by s-frame 64.

FIG. 5 is a front elevational perspective view of a close-up of the cutting wheel assembly, showing the relative placement of cut wheel 58 and feed wheel 66. Cut wheel 58 is being held in place by cut wheel shaft 56, which is a free rolling shaft. Feed wheel 66 is being driven by transmission 48 within transmission cover housing 50. S-shaped frame 64 is clearly shown as a securement for all other elements. Feed wheel guard 52 shields any bits from flying off and hurting the operator, while cut wheel guard 60 performs the same function for cut wheel 58.

FIG. 6 shows a perspective detail of the transmission portion of the throatless power rotary shear invention, including a feed wheel transmission shaft 70 driving a beveled gear 72. Beveled drive gear 74 rotates about bevel drive gear shaft 76 which is driven by drive gear teeth 78. Transmission housing 80 houses the entire beveled gear assembly. Gear teeth 82 communicate with drive gear teeth 84 to rotate feed wheel transmission shaft 70. Transmission 86 generally indicates the entire transmission assembly including the gears.

FIG. 7A is a close-up perspective view of cut wheel 88 and its relative placement with regard to feed wheel 90. Cut wheel shaft 92 secures cut wheel 88 in position, biasing cut wheel 88 with regard to feed wheel 90. Cut wheel shaft guard 94 is secured to s-shaped frame 98. V-shaped relief 100 is shown having a relatively vertical dimension, while upper ramp 102 is essentially about 45° to the vertical, while lower ramp 104 is 45° to the horizontal. Varying angles are anticipated by the inventor, depending upon suitability for a particular cutting job. As material to be cut is fed between cut wheel 88 and feed wheel 90, the cut material is urged upwardly by upper ramp 102, while the other cut piece is urged downwardly by lower ramp 104. This v-shaped relief behind cut wheel 88 and feed wheel 90 better direct the flow of cut material, resulting in a smooth cut. There is a slight gap behind the cutting wheel in order to allow for cut corrugated materials to separate. Transmission housing 96 encases the entire transmission assembly including the gears.

FIG. 7B is the same view as that shown in FIG. 7A, but without the cut wheel 88 and feed wheel 90, in order to more clearly detail the v-shaped relief behind the cutting wheels. In order to appreciate one of the benefits of the present invention, the material exit geometry is more easily understood with the angle of exit via the upper ramp 102 and the material exit downwardly by lower ramp 104. Upper and lower ramps 102 and 104 respectively are formed into s-shaped frame 98.

FIG. 8 is a rear elevational view of the s-shaped frame 106 having a vertical lower component 108, a horizontal portion 110 and interior frame outside radius 112 opposite inside radius 114. Cut wheel 116 is attached to cut wheel shaft 118. Cut wheel 116 is urged against feed wheel 120, which is driven by feed wheel shaft 122 and it is in communication with the transmission inside transmission housing 124. The ratio of the height of the s-shaped frame vertical 106 versus the s-shaped frame horizontal 110 is from 10 to 1 to 0.5 to 1, and most preferably from 4 to 1 to 1 to 1. These ranges of height-width ratios define the most suitable clearances for the cut wheel, the feed wheel and the material being cut, although any other ratio may be more suitable for a particular application.

FIG. 9 illustrates yet another aspect of the present invention generally denoted by numeral 130, illustrating a bench mount for the throatless power rotary shear of the present invention. Bench mount apparatus 130 may be attached to a wooden support 132, such as on a sawhorse. A mount attachment bracket 134 may include thumbscrews 136 or any other suitable mount attachment bracket fasteners. My throatless power rotary shear is secured onto mount attachment bracket 134 in a suitable configuration so that the material that is being cut may be fed through the cutting and feed wheels. Clearly, my throatless power rotary shear can be mounted on a bench, a wall, the tailgate of a pickup truck, or any place else that is convenient for the operator.

A preferred aspect of the present application includes a throatless power rotary shear including a portable motorized, weight balanced, power shears capable of being used single-handedly to provide smooth cuts between a cut wheel and a feed wheel. A v-shaped relief behind the cut wheel and the feed wheel separates any of the various cut materials to better direct the flow of the cut material, resulting in a smooth cut. An integral s-shaped frame has a clearance for better material flow and a developed width between two vertical stanchions to optimize flow of cut materials. The s-shaped frame includes an upper and a lower ramp incorporated and integral within the s-shaped frame.

Due to the combination of the v-shaped relief and the integral s-shaped frame, the power shears are capable of being used as a balanced single handed hand tool. In this aspect, the v-shaped relief is preferably formed into the s-shaped frame including an upper ramp and a lower ramp to separate the material after cutting. In addition, the combination configuration of the v-shaped relief along with the s-shaped frame enable an operator to make any type of cut, whether it be an angled cut or even perpendicular cuts for cutting around chimney flashing or the like. The power shears may include a gap of distance, A-A, between the exit point of the cut wheel and the feed wheel and the upper and lower ramps incorporated and integral within the s-shaped frame. Preferably, the gap of distance, A-A, in the s-shaped frame of the power shears is from ⅛ inch to 1 inch, preferably three quarters of an inch for sheet metal roofing having corrugated incline positions.

Prior art rotary cutting shears have been designed mostly for cutting cloth, which is extremely flexible and is easy to remove and separate the pieces being cut. However, when one is cutting a rigid construction material, such as metal roofing, fiberglass, plastic sheets or other hard and rigid materials, separating the pieces after they've been cut is much more difficult. Not only does it become tangled, but because the material is rigid, after it is cut, it provides a danger to the operator because his fingers may become cut on the sharp edges. Clearly, this is not the case when cutting cloth. Therefore, these pieces of prior art do not necessarily apply to solve the problem to which the present invention is addressed.

When an operator cuts a corrugated rigid material, the cutting surfaces ride up the incline of the corrugated area, and then ride down on the opposite side of the incline of the corrugation itself. During this operation, the corrugated component is urged downward in prior art devices, which causes a problem. By the downward urging of the rigid corrugated material after it has been cut, the cut portion becomes entangled in the machinery. The present invention alleviates this issue by including a v-shaped relief in the frame of the tool immediately adjacent to the cutting wheels contact point. By using an s-shaped frame that includes the v-shaped relief, material is separated downward on one half and upward on the other, providing a clean separation. This clean separation also allows for easily backing the tool out of the cutting area by using a reverse gear that is motorized.

Prior art devices feed material that is to be cut between two sheer wheels where it is severed and then passed below the motor housing. The cutting edges of the two rotary shears are biased together at their point of contact to provide a positive shearing action. A cover is provided to protect the bearings of the driving shear wheel also act to direct cut material so that it does not “hang up” on the leading edge of the bracket. An additional bearing shield disposed over the bearing of the driving shear wheel is provided with a depending portion which serves to direct the remaining portion to cut material by the leading edge of the bracket. For very flexible materials, this is appropriate and acceptable, however, when cutting more rigid material, especially corrugated rigid material, the cut material becomes hung up, and is not easily separated, nor is it easy to back the tool out of the cutting operation.

When an operator is having to make angled cuts, such as a right angle in order to fit around a square chimney or the like, the operator goes forward and cuts the material, the v-shaped relief frame separates the material on one side downwardly and opposite side upwardly and provides a reverse gear so that the tool can easily be backed out to prevent further cutting. Then, cutting can come in from the 90° angle and easily make a 90° angle cut, to shape the rigid material, as desired, depending upon the particular issue during construction. As in the prior art devices, however, all of the severed material passes below the motor housing and frame of the tool.

In summary, numerous benefits have been described which result from employing any or all of the concepts and the features of the various specific aspects of the present invention, or those that are within the scope of the invention. The present invention of a throatless power rotary shear acts perfectly to provide smooth cuts, without injuring the operator.

The foregoing description of a preferred aspect of the invention has been presented for purposes of illustration and description. It is not intended to be to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings with regards to the specific aspects. The aspect was chosen and described in order to best illustrate the principles of the invention and its practical applications to thereby enable one of ordinary skill in the art to best utilize the invention in various aspects and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims which are appended hereto.

INDUSTRIAL APPLICABILITY

The present invention finds utility in the construction industry as well in the home modification industries. 

What is claimed is:
 1. A throatless power rotary shear, comprising: a portable motorized, weight balanced, power shears capable of being used single-handedly to provide smooth cuts between a cut wheel and a feed wheel; a v-shaped relief behind the cut wheel and the feed wheel for separating various cut materials to better direct the flow of the cut material, resulting in a smooth cut; and an s-shaped frame having a clearance for better material flow and a developed width between two vertical stanchions to optimize flow of cut materials, said s-shaped frame including an upper and a lower ramp incorporated and integral within the s-shaped frame.
 2. The throatless power rotary shear of claim 1, wherein the power shears are capable of being used as a balanced single handed hand tool.
 3. The throatless power rotary shear of claim 1, wherein the power shears further comprise a reversible setting in the motor to back out of a cut material.
 4. The throatless power rotary shear of claim 1, wherein the v-shaped relief is formed into the s-shaped frame including an upper ramp and a lower ramp to separate the material.
 5. The throatless power rotary shear of claim 1, wherein the power shears include a gap of distance, A-A, between the exit point of the cut wheel and feed wheel and the upper and lower ramps incorporated and integral within the s-shaped frame.
 6. The throatless power rotary shear of claim 5, wherein the gap of distance, A-A, in the s-shaped frame of the power shears is from ⅛ inch to 1 inch, preferably three quarters of an inch for sheet metal roofing having corrugated incline positions. 